Enhanced displacement of [3H]imipramine, but not [3H]paroxetine binding by plasma from depressed patients.
Plasma from healthy subjects inhibited the binding of [3H]imipramine competitively and [3H]paroxetine non-competitively to platelet membranes in a volume-dependent manner. Plasma from 40 depressed patients was more effective at inhibiting [3H]imipramine, but not [3H]paroxetine, binding compared to plasma from matched controls. This difference was not related to recent antidepressant treatment. The results suggest that the concentration of an endogenous modulator of [3H]imipramine binding is increased in depressive illness. The concentration of alpha 1-acid glycoprotein, a proposed endogenous modulator of [3H]imipramine binding, did not differ between depressed patients and controls. Our results suggest that factors other than alpha 1-acid glycoprotein may modulate [3H]imipramine binding.
Lawrence
K M
KM
Department of Pharmacology and Clinical Pharmacology, St. George's Hospital Medical School, London, UK.
Lowther
S
S
Falkowski
J
J
Jacobson
R R
RR
Horton
R W
RW
D000328:Adult; D001667:Binding, Competitive; D001792:Blood Platelets / Q000737:chemistry / Q000378:metabolism; D001798:Blood Proteins / Q000378:metabolism* / Q000502:physiology; D002462:Cell Membrane / Q000737:chemistry / Q000378:metabolism; D003866:Depressive Disorder / Q000097:blood* / Q000378:metabolism; D005260:Female; D006801:Humans; D007099:Imipramine / Q000378:metabolism*; D005779:Immunodiffusion; D008297:Male; D008875:Middle Aged; D009961:Orosomucoid / Q000032:analysis / Q000378:metabolism; D017374:Paroxetine / Q000378:metabolism*; D010980:Platelet Membrane Glycoproteins / Q000032:analysis / Q000378:metabolism; D011869:Radioligand Assay; D011985:Receptors, Serotonin / Q000378:metabolism*; D014316:Tritium
D001798:Blood Proteins; D009961:Orosomucoid; D010980:Platelet Membrane Glycoproteins; D011985:Receptors, Serotonin; D014316:Tritium; D017374:Paroxetine; D007099:Imipramine